Reactions of Rhenium(V) Polyhydride Complexes with Dialkyl

Reactions of Rhenium(V) Polyhydride Complexes with Dialkyl. Acetylenedicarboxylates. X-ray Crystal Structure Analysis of. Re(q2( C,O)-C(CO,Me) =CHCO ...
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Organometallics 1992, 11, 1963-1967

1963

Reactions of Rhenium(V) Polyhydride Complexes with Dialkyl Acetylenedicarboxylates. X-ray Crystal Structure Analysis of Re(q2(C,O)-C(CO,Me) =CHCO,Me)(MeO,CCH=CHCO,Me)(ttp)*MeOH (ttp = PhP(CH,CH,CH,PPh,),) Youhyuk Kim, Judith Gallucci, and Andrew Wojcicki" Department of Chemistry, The Ohio State University, Columbus, Ohio 43210 Received October 15, 1991

Summary: ReH,(Cyttp) (Cyttp = PhP(CH,CH,CH,PCy,),) reacts with R O p C m C 0 2 Rin excess in benzene solution at room temperature to yield ReH,(RO,CCH= CHC0,RXCyttp) (R = Me, la: R = Et, lb). Similarly conducted reactions of ReH,(ttp) (ttp = PhP(CH,CH2CH,PPh2)2) with RO,CmCO,R afford Re(v2(C,O)-c(CO~)=cHcO~~RO~CCH=cHco,R)(tt~) (R = Me, 2a; R = Et, 2b). Crystal data for 2a.MeOH: P2,ln, a = 10.988 (2) A, b = 20.648 (2) A, c = 20.494 (2) A, j3 = 92.61 (1)': V = 4645 A3: Z = 4, R = 0.040, R , = 0.042 for 6243 reflections with Fo2 > 3a(FO2).

Whereas insertion reactions of transition-metal monoand dihydride complexes with alkynes to generally afford metal-vinyl complexes' have been well investigated, reactions of polyhydride complexes with alkynes have been less explored.2 As part of our continuing investigations into the chemistry of rhenium hydride complexes containing tridentate phosphine we examined the behavior of ReH,(Cyttp) (Cyttp = P h P (CH2CH2CH2PCy2)2)and ReH5(ttp) (ttp = PhP(CH2CH2CH2PPh2)2) toward RO2CC=CCOzR (R = Me (DiMAD), Et (DEAD))? Reported here are our synthetic, spectroscopic, and X-ray crystallographic results.

Results and Discussion Treatment of ReH,(Cyttp) with excess R 0 2 C M C 0 2 R in benzene solution at room temperature affords the yellow compounds la (R = Me) and l b (R = Et) (Scheme I). Both compounds were characterized by 'H, 2H,13C{'H],and 31P(1H]NMR and IR spectroscopic methods and by elemental analysis (cf. Experimental Section). They are derived from the parent ReH,(Cyttp) by replacement of two hydrido ligands with a molecule of R02CCH= CHC02R,obtained by hydrogenation of R02CC=CC02R. NMR spectroscopic data for 1 are consistent with a pentagonal-bipyramidal structure, similar to that reported for ReH3(cyclopentene)(PMe2Ph)3,6in which the like substituents at the C=C bond of the alkene are trans (i.e., fumarate R02CCH=CHC02R).In our structure, the two wing P atoms occupy axial positions, and the central P (1) (a) Collman, J. P.; Hegedus, L. S.; Norton, J. R.; Finke, R. G . Principles and Applications of Organotransition Metal Chemistry; University Science Books: Mill Valley, CA, 1987. (b) Otauka, S.; Nakamura, A. Adu. Organomet. Chem. 1976,14, 245. (2) (a) Bianchini, C.; Meli, A.; Peruzzini, M.; Vizza, F.; Albinati, A. Organometallics 1990, 9, 2283. For reactions of metal hydridwdihydrogen complexes with alkynes see, e.g.: (b) Bianchini, C.; Meli, A.; Peruzzini, M.; Vizza, F.; Zanobini, F. Organometallics 1989,8,2080. (c) Marinelli, G.; El-Idrissi Rachidi, I.; Streib, W. E.; Eisenstein, 0.;Caulton, K. G. J.Am. Chem. SOC.1989,111,2346. (d) Jia, G.; Rheingold, A. L.; Meek, D. W. Organometallics 1989, 8, 1378. (e) Jia, G.; Meek, D. W. Organometallics 1991, 10, 1444. (3) Kim, Y.; Deng, H.; Meek, D. W.; Wojcicki, A. J . Am. Chem. SOC. 1990,112, 2798. (4) Kim, Y.; Gallucci, J.; Wojcicki, A. J. Am. Chem. SOC. 1990, 112. 8600. (5) The structure of ReH,(Cyttp) and other reactions of ReH,(Cyttp) and ReH,(ttp) will be reported in separate papers: Kim, Y.; Gallucci, J.; Wojcicki, A. To be submitted for publication. (6) Green, M. A.; Huffman, J. C.; Caulton, K. G.; Rybak, W. K.; Ziblkowski, J. J. J . Organomet. Chem. 1981,218, C39.

Scheme I CY2

CY2

l a , R = Me; l b , R

=

Et

2 a , R = Me: 2 b , R = Et

atom, the three hydrides, and the midpoint of the C 4 bond of the alkene take up the five equatorial sites (cf. Scheme I). This arrangement gives a noticeably unsymmetrical disposition of the different donor atoms in the coordination sphere of Re. Accordingly, the 'H NMR spectra show two inequivalent Me and (alkene) CH2 (for lb) groups, and the 13C{lH)NMR spectra reveal two inequivalent CO, (alkene) CH, Me, and (alkene) CH2 (for lb) groups. The 31P{1H)NMR spectra of la and l b show three signals each, thus further supporting the proposed structure. The 'H NMR spectra also exhibit two metal hydride resonances with the relative intensities 1:2. The presence of coordinated R02CCH=CHC02R is evidenced by the NMR spectroscopic data. The alkene CH 'H NMR signals could not be observed because of an overlap with one of the Me signals. However, the ?HNMR spectrum of partially deuterated la-prepared by the reaction of ReH,DkX(Cyttp)' (r 1) with DMAD-in C6H6 solution reveals the presence of the alkene CD deuterium atoms by a broad signal at 6 3.12 ppm, which occurs along with the signals of the ReD deuterium at 6 -5.95 and -7.24 ppm (relative intensities 21:2, respectively). The chemical shift of the alkene CH (CD) is comparable to those of RU((Z)-M~O~CCH=CHCO~M~)(CO)~ (6 3.73 ppm) and Ru((E)-Me02CCH=CHC02Me)(C0)4 (6 3.05 ppm).8 The presence of Me02CCH=CHC02Mein la is confirmed by the broad-band decoupled 13C DEPT spectra. In the aliphatic region, a t 6 41.25-26.57 ppm, resonances corre-

-

(7) Obtained from [ReH,D+,(Cyttp)]SbF, (nonclassical structure, x

= 1) and excess NEta [ReH,D+ (Cyttp)]SbFe was prepared by hydrogen-deuterium exchange of [Re(&H,)H,(Cyttp)]SbF: with excess D20 in deuterated benzene. Details of these experiments will be published

elsewhere., (8) Grevels, F.-W.; Reuvers, J. G . A.; Takats, J. J. Am. Chem. SOC. 1981,103, 4069.

0276-7333/92/2311-1963$03.00/00 1992 American Chemical Society

Notes

1964 Organometallics, Vol. 11, No. 5, 1992

Table I. Selected Bond Distances (A) and Angles (deg) for 2a MeOH Re-P(1) Re-P(2) Re-P(3) ReO(6) RWC(9) Re-C(10)

C

Figure 1. ORTEP drawing of 2a showing the atom-numbering scheme. The non-hydrogen atoms are drawn at the 50% probability level, and the hydrogen atoms are omitted.

sponding to six CH carbon atoms are observed. Four of them are assigned to the ipso carbons of the Cy groups of Cyttp on the basis of large values of Jcp (14.8-31.0 Hz). The remaining two resonances at 6 29.85 and 26.57 ppm with smaller values of Jcp (9.1 and 6.6 Hz, respectively) are those of the alkene CH carbon atoms. These signals show larger upfield coordination shiftsgcompared to those of Ru((Z)-M~O~CCH=CHCO,M~)(CO)~ and Ru((E)Me02CCH=CHC02Me)(C0)4(6 37.1 and 38.7 ppm, respectively),* suggesting considerable P bonding from the metal center to the alkene ligand. The different chemical shifts of the alkene CH carbon atoms further support the fumarate structure of R02CCH=CHC02R. Intramolecular migration of hydride to an alkene is generally a facile process.10 In this context, la and lb are interesting examples of metal alkene polyhydride complexes where such a migration does not occur under ambient conditions. Other examples of such rhenium complexes are R ~ H ~ ( C Z H ~ ) ~and (PR ReH5(C2H4)(PRd2 ~)Z (PR3 = PPh(i-Pr), P (cyclopentyl),) .I1 The behavior of ReHS(ttp) toward excess RO,CC= CCOzRin benzene at room temperature differs from that of ReH,(Cyttp) in that 2 equiv of the alkyne is ccnsumed to give the dark brown compounds 2a (R = Me) and 2b (R = Et) (Scheme I). The structure of 2a.MeOH in the solid state was determined by an X-ray crystallographic analysis. An ORTEP drawing of 2a is shown in Figure 1, and selected bond distances and angles are given in Table I. The molecules of 2 s are comprised of a rhenium atom surrounded by the tridentate ttp, (E)-Me02CCH= CHCOzMe, and the vinyl ligand q2(C,0)-C(C02Me)= CHC02Me. The overall geometry around the rhenium center is that of a distorted octahedron, if the alkene is assumed to occupy a single coordination position. The three P atoms are bound to Re in a meridional fashion, the P-Rep angles being 87.91 (6)' (P(l)-Re-P(2)), 88.34 (6)' (P(2)-Re-P(3)), and 174.35 (5)O (P(lbReP(3)). The (9) The corresponding chemical shifts for free dimethyl maleate and dimethyl fumarate are 6 130.1 and 133.5 ppm, respectively; see Sadtler standard carbon-13 NMR spectra Nos. 164 (in CDC13)and 229 (in CDCls). (10) Reference la, p 383. (11) Hazel, N. J.; Howard, J. A. K.; Spencer, J. L. J. Chem. SOC., Chem. Commun. 1984, 1663.

P(l)-Re-P(2) P(l)-Re-P(3) P(l)-Re-0(6) P(l)-Re-C(9) P(1)-Re-C(1O) P(l)-Re-C(15) P(2)-Re-P(3) P(2)-Re-0(6) P(2)-Re-C(9) P(2)-Re-C(10) P(2)-Re-C(15) P(3)-Re-0(6) P(3)-Re-C (9) P(3)-Re-C(10) P(3)-Re-C(15) 0(6)-Re-C(9) 0(6)-Re-C(10) 0(6)-Re-C(15) C(g)-Re-C(lO) C(9)-Re-C(15) C(lO)-Re-C(15) C(7)-0(1)-C(8) C(11)-0(4)-C(12) C(13)-0(5)4(14)

Bond Distances 2.435 (2) Re-C(l5) 2.444 (2) 0(5)-C(14) 2.446 (2) 0(6)-C(14) 2.243 (4) 0(7)-C(17) 2.210 (6) C(9)-C(lO) 2.151 (6) C(14)-C(15)

2.115 (7) 1.312 (8) 1.239 (8) 1.236 (9) 1.459 (9) 1.482 (9)

Bond Angles 87.91 (6) Re-O(6)-C(14) 174.34 (5) C(17)-0(8)-C(18) 88.6 (1) O(l)-C(8)-0(2) 90.5 (2) O(l)-C(8)-C(9) 93.7 (2) 0(2)-C(8)-C(9) 90.2 (2) Re-C(9)-C(8) 88.34 (6) Re-C(S)-C(lO) 87.1 (1) C(8)-C(9)-C(10) 81.5 (2) Re-C(lO)-C(g) 120.5 (2) Re-C(lO)-C(ll) 150.2 (2) C(9)-C(lO)-C(ll) 87.0 (1) 0(3)-C(ll)-0(4) 93.1 (2) 0(3)-C(ll)-C(lO) 91.8 (2) 0(4)-C(ll)-C(lO) 91.0 (2) 0(5)-C(14)-0(6) 168.6 (2) 0(5)-C(14)-C(15) 152.3 (2) 0(6)-C(14)-C(15) 63.1 (2) Re-C(15)-C(14) 39.1 (2) Re-C(15)-C(16) 128.3 (3) C(14)-C(15)4(16) 89.3 (3) C(15)-C(16)-C(17) 116.6 (7) 0(7)-C(17)-0(8) 116.0 (7) 0(7)-C(17)-C(16) 116.2 (7) 0(8)-C(17)-C(16)

91.5 (4) 118.4 (7) 119.7 (7) 113.4 (6) 126.9 (8) 130.5 (5) 68.3 (4) 120.2 (6) 72.7 (4) 126.4 (5) 114.1 (6) 122.2 (7) 126.7 (7) 111.0 (6) 121.1 (7) 124.9 (7) 113.7 (6) 90.4 (4) 128.1 (7) 128.1 (7). 129.4 (7) 120.4 (8) 121.8 (8) 117.6 (7)

vinyl C(15) atom coordinates to Re in the same plane as P(1), P(2), and P(3), whereas the vinyl a-carboxylate oxygen, 0(6), takes up one position cis to these P and C donors and the alkene C=C fills the other. The relative orientation of the COzMe substituents in Me0,CCHCHCOzMeis trans (the torsion angle C(8)-C(9)-C(lO)-C(11)is -111.9 (7)O);thus, the ligand is dimethyl fumarate (or E). Its C(9)-C(lO) bond distance of 1.459 (9) A is appreciably longer than that found in Na[Co(CO)2((E)Me02CCH==CHC02Me)2].THF(1.38 (2) A average)12and Ni((E)-Et02CCH=CHC0,Et)(MeCN) (1.39 (1) A)13 to indicate substantial Re-to-alkene A bonding. The Re-C(15) bond distance of 2.115 (7) A is slightly shorter than the corresponding ReC(viny1) bond distance in CpzRe(v1-(Zor E)-C(C02Me)=CHC02Me)(2.153 (6) and 2.156 (7) A, re~pectively).'~The -9 (1)O torsion angle for C(14)-C(15)-C (16)-C(17) indicates cis (Le., ( E )-ReC(C02Me)=CHC02Me) stereochemistry around the C=C double bond of the vinyl ligand. Although a large number of metal-alkene and metalvinyl compounds have been characterized,' 2a represents an unusual example of a complex containing both an alkene and a vinyl ligand at the same metal center. 'H and 13C{'H)NMR spectra of 2a reveal fluxional behavior in solution. The 'H NMR spectrum in C6D6at 30 OC shows the expected signals of the vinyl ligand at 6 7.96 (CH), 3.64 (Me), and 2.54 (Me) ppm. The chemical shift of the CH proton is comparable to that of trans-PtH(PR3)2(~'-C(C02Me)=CHC02Me) (PR3 = PCy,, P(i-Pr),, 6 7.71, 7.42, 7.23, 7.31 ppm, P ( ~ - B U ) ~ ( ~ - P(t-Bu),Me; BU), re~pectively).'~The alkene ligand resonances occur as broad peaks at 6 4.70 (CHI and 3.07 (Me) ppm. In CD2C12 (12) Ungvtiry, F.; Gallucci, J.; Wojcicki, A. Organometallics 1991,10, 3053. (13) Baasai, J. W.; Calcaterra, M. J. Organomet. Chem. 1976,110,1!29. (14) Herberich, G. E.;Barlage, W. Organometallics 1987, 6, 1924. (15) Clark, H. C.; Ferguson, G.; Goel, A. B.;Janzen, E.G.; Ruegger, H.; Siew, P. Y.; Wong, C. S. J. Am. Chem. SOC.1986,108,6961.

Organometallics, Vol. 11, No. 5, 1992 1965

Notes solution, the CH peak (now at 6 4.42 ppm) is even broader, and the Me peak is nonobservable. Cooling the CDzC12 solution to -50 "C results in the sharpening of the CH signal-now a triplet ( J H p = 7.8 Hz) at 6 4.35 ppm-and the appearance of the Me signal at 6 3.48 (br) ppm. Also, the resonance at 6 2.66 ppm of one of the vinyl ligand Me groups (probably C(0Me)ORe) occurs as a doublet (JHP = 2.2 Hz). There are no signals in the metal hydride region of the spectrum. The 13C(lH)NMR spectrum of 2a in CD2C12solution at 30 OC shows the expected signals of the vinyl ligand carbon atoms (cf. Experimental Section) as well as a broad signal of the alkene ligand Me groups at 6 50.55 ppm. When the solution is cooled to -90 OC, the latter signal changes to two singlets, wid additional resonances appear at 6 185.84, 182.96 (2 alkene ligand CO's), 36.42 (br), and 28.89 (br, HC-CH) ppm. Thus, both 'H and 13C('H}low-temperature NMR spectra are in accord with the solid-state structure of 2a. In contrast, 31P(1HJNMR spectra of 2a in CD2C12display essentially no changes on cooling the solution from +30 to -50 OC. Thus, the fluxionality would appear to involve only the coordinated alkene. It seems likely that rotation of Me02CCH=CHC02Me about the metal-alkene bond axis is occurring.16 When the reaction between ReH,(ttp) and Me02CC= CC02Me was conducted at 0 "C with warming to room temperature and for a shorter period of time, an unstable orange solid (3a) was isolated. This solid undergoes conversion to 2a on storage in solution. Its 'H NMR spectrum shows three sharp singlets at 6 3.42, 2.88, and 1.56 ppm with the relative intensities 1:1:2 for the Me groups and a triplet ( J H p = 6.2 Hz) at 6 4.26 ppm for the alkene CH groups. A vinyl CH resonance could not be located, probably because of the Ph resonances. There are no metal hydride resonances. The 31P(1H}N M R spectrum is similar to that of 2a, in that three resonances with a large coupling between the wing P atoms (Jpz4 = 179.2 Hz)are observed. Whereas it seems probable that this compound is isomeric with 2a, possibly ita maleate analogue, a specific structural assignment cannot be proposed from these limited spectroscopic data. The difference in reactivity between ReH,(Cyttp) and ReH,(ttp) toward R02CC=CC02R may be attributed to the lower electron density at the metal in ttp-containing complexes. By analogy with the behavior of ReH5(Cyttp), it seems likely that the initial product of the reaction of ReH,(ttp) with R02CCrCC02R is ReH3(R02CCH= CHC02R)(ttp). Since ttp is a weaker electron-donating ligand compared to Cyttp, this intermediate would be more susceptible than 1to formation of an q2-Hzcomplex17and reductive elimination of H2 to generate a 16-electron reactive species. Such a species would then combine with a second molecule of R02CC=CC02R to afford the insertion product 2 (by intermediacy of 3). Although this rationale appears attractive, a greater steric demand of the Cyttp ligand than of the ttp ligand may also contribute to the reaction of ReH5(Cyttp) stopping at the trihydride stage.

Experimental Section General Procedures. All reactions and sample manipulations were carried out under an atmosphere of Ar by use of standard ~~~

~

~

~

(16)For alkene rotation in metal complexes see, e.g.: Cotton, F. A. In Dynamic Nuclear Magnetic Resonance; Jackman, L. M., Cotton, F. A., Eds.; Academic Press: New York, 1975;p 377. (17)For $-Hz metal complexes see, e.g.: Crabtree, R. H.; Hamilton, D. G. Adu. Organomet. Chem. 1988,28, 299.

procedures.18 Elemental analyses were performed by M-H-W Laboratories, Phoenix, AZ. Infrared (IR) spectra were recorded on a Perkin-Elmer Model 283B grating spectrophotometer as Nujol mulls between KBr plates and were calibrated with polystyrene. NMR spectra were collected on a Bruker AM-250 or AM-500 spectrometer. Residual proton or carbon-13 resonances in deuterated solvents were used as internal standards for the 'H and 13C NMR spectra. Phosphorus-31 chemical shifts are referenced to external 85% H3P04. Materials. AU solvents were purified by distillation under an Ar atmosphere according to literature procedure^.'^ Reagents were obtained from commercial sources and used as received, except as noted below. The tridentate ligands Cyttp (PhP( C H ~ C H ~ C H ~ P C Yand , ) ~ ttp ) (PhP(CH&H&H2PPh,),) were prepared by use of slightly modified literature procedures.20 ReC13(PMePh2)3was obtained from NaRe04, PMePh,, and concentrated HCI in absolute ethanol.,l Preparation of ReC13(Cyttp).To a solution of Cyttp (2.24 in 100 mL of benzene was added ReC13(PMePh2)3 g, 3.81 "01) (3.00 g, 3.36 mmol), and the mixture was kept at reflux for 8-12 h to give a red-brown solution. The solution was then concentrated under reduced pressure, and ca. 100 mL of EbO was added to result in the formation of a yellow powder. The powder was collected on a filter frit, washed with a small amount of EtO, and dried under vacuum overnight: yield 2.72 g (92%); 'H NMR (CD2C12)6 29.0 to -10.0; 31PNMR spectrum not observed. Anal. Calcd for C36H61C13P3Re:C, 49.17; H, 6.99; C1, 12.09; P, 10.56. Found: C, 49.41; H, 7.06; C1, 11.91; P, 10.72. Preparation of ReClJttp). The title complex was prepared similarly to ReC13(Cyttp) from ReC13(PMePhJ3 (2.50 g, 2.80 "01) and ttp (1.77 g, 3.15 "01): yield 2.10 g (88%)of a yellow powder; 'H NMR (CD2C12)6 27.3 to -8.4; 31PNMR spectrum not C, 50.56; H, 4.36; C1, observed. Anal. Calcd for C36H37C13P3Re: 12.44. Found: C, 50.42; H, 4.37; C1, 12.61. Preparation of ReH,(Cyttp). A suspension of ReC13(Cyttp) (2.00 g, 2.27 mmol) and excess NaBH., (1.03 g, 27.3 mmol) in 60 mL of absolute ethanol was kept at reflux for 8-12 h until the yellow complex dissolved and the formation of a white solid was observed. The reaction mixture was cooled to room temperature, and the white solid was collected on a filter frit and washed first with 20 mL of H 2 0 and then with 20 mL of ethanol. It was dried overnight under vacuum; yield 1.15 g (65%). Analytically pure product can be obtained by slow evaporation of the solvent from a saturated benzene solution under a flow of argon: IH NMR (CsDs, no cyttp signals) 6 -7.66 (td,JHp. = 19.4 Hz, J H=~13.7 HZ, R ~ H & (P, = central P atom, P, = wing P atom); 3 1 ~ ( 1 1 4NMR 6 24.17 (d, Jpp, = 15.1 Hz, P,), 1.80 (t,J p p , = 15.1 Hz, P,). Anal. Calcd for c3&IsBP3Re: C, 55.57; H, 8.55; P, 11.94. Found: C, 55.63; H, 8.69; P, 11.71. Preparation of ReH,(ttp). The title complex was prepared similarly to ReH&yttp) from ReC13(ttp) (2.70 g, 3.16 "01) and N&H4 (1.43 g, 37.8 mmol): yield 1.60 g (67%) of a pale yellow no ttp signals) 6 -5.93 (td,J H p = 19.9 powder; 'H NMR (c&& ~ 12.3 Hz, ReH,); 31P(1H1NMR (C6D6)6 11.34 kd, Jp Hz, J H = = 15.0 kz, Pw),-8.53 (t, Jpep, = 15.0 Hz, PJ. Anal. Calcd C3,&P3Re: C, 57.36; H, 5.62. Found: C, 57.12; H, 5.64. Reaction of ReH,(Cyttp) with Me02CC=CC02Me (DMAD). To a solution of ReH5(Cyttp) (0.10 g, 0.13 mmol) in 25 mL of benzene was added excess DMAD (0.10 mL, 0.81 mmol), and the mixture was stirred for 30 min. The resulting pale yellow solution was concentrated to ca. 2 mL under reduced pressure, 10 mL of methanol was added, and the mixture was stirred for 30 min to give a yellow precipitate. The solid was collected on a fiiter frit, washed with a small amount of EtO, and dried under vacuum overnight: yield of ReH3(MeO2CCH=CHCO2Me)(Cyttp) (la) 0.13 g (54%); IR (cm-', Nujol) u(ReH) 1965 (w), 1910 (w), v(C=O) 1725 (m), 1690 ( 8 ) ; 'H NMR (CsD6,no Cyttp signals) 6

(c&)

&:

(18)Shriver, D. F.;Drezdzon, M. A. The Manipulation of Air-Sensitiue Compounds, 2nd ed.; Wiley: New York, 1986. (19)Perrin, D. D.; Armarego, W. L. F.; Perrin, D. R. Purification of Laboratory Chemicals; Pergamon Press: Oxford, U.K., 1966. (20)Uriarte, R.;Mazanec, T. J.; Tau, K. D.; Meek, D. W. Inorg. Chem. 1980,19, 79. (21)(a) Chatt, J.; Leigh, G. J.; Mingos, D. M. P.; Paske, R. J. J. Chem. SOC.A 1968,2636. (b) Chatt, J.; Leigh, G. J.; Mingos, D. M. P. J.Chem. SOC.A 1969,1674.

1966 Organometallics, Vol. 11, No. 5, 1992 Table 11. Crystal Data and Data Collection and Refinement Details for 2a MeOH Crystal Data 92.61 (1) formula C49HM09P3Re 8, deg v, A3 4645 fw 1068.1 space group R 1 / n z 4 Ddd, g cm-3 1.53 a, A 10.988 (2) b, A 20.648 (2) cryst size, mm 0.15 X 0.31 X 0.38 linear abs coeff, 28.05 c, A 20.494 (2) cm-' Data Collection and Refinement temp, "C 23 radiatn Mo Kn,graphite monochromated transmissn factors 0.71-1.00 28 limits, deg 4-55 8, with max of 4 scans/rfln scan speed, deg min-' (in w ) bkgd time/scan time 0.5 scan range, deg (in w ) 1.20 + 0.35 tan 9 data collected +h,+k,&l no. of unique data 10979 6243 no. of unique data (F: > 3@,2)) no. of variables 549 w scan type R(F)' 0.040 R,Wb 0.042 error in abservn of unit wt, e 1.18

zllFol i~cll/n~ol. bRw(F) =

"HF)= xwlF,,12]i/2, with w = l/a2(Fo).

[z:w(lFoI - lFc1)2/

3.52 (s, Me), 3.10 (s,Me),-5.92 (td,Jm= 30.2,5.5 Hz,ReH), -7.26 (m, 2 ReH); 31P(1HJ( c a s ) 6 25.96 (d, Jpzw= 35.6 Hz, Pw),-8.80 (t, Jp,p, = 35.6 Hz, PJ, -10.68 (d, Jpz, = 35.6 Hz, Pw);13C(1H] NMR (C6D6,no Cyttp signals) 6 182.22 (s, CO), 180.81 ( 8 , CO), 49.95 (s, Me), 49.86 ( 8 , Me), 29.80 (t, Jcp = 9.1 Hz, =CH), 26.60 C, 54.82; (d, Jcp= 6.6 Hz, =CH). Anal. Calcd for C42H7204P3Re: H, 7.89; P, 10.10. Found: C, 55.06; H, 7.69; P , 9.96. Reaction of ReH,(Cyttp) with EtOzCC=CCOzEt (DEAD). The reaction procedure and workup were analogous to those in the preceding synthesis. From 0.10 g (0.13 "01) of ReH&Cyttp) and 0.10 mL (0.62 mmol) of DEAD, 0.052 g (42%) of product, ReH3(Et0,CCH=CHC02Et)(Cyttp)(lb), was obtained. l b is very soluble in most common organic solvents: IR (cm-', Nujol) u(ReH) 1965 (w), 1895 (w), v(C=O) 1739 (m), 1690 (9); 'H NMR (C&, no Cyttp signals) 6 4.09 (m, CH&, 3.86 (m, CH2),3.08 (s, HC=CH), 1.14 (t, Me), 0.78 (t, Me), -5.98 (td, J H p = 33.6, 6.3 Hz, ReH), -7.33 (m, 2 ReH); 31P(1H)NMR (Cp,) 6 26.30 (d, J p 8 . = 38.5 Hz, Pw),-9.47 (t,Jpz = 38.5 Hz, PJ, -10.97 (d, Jp,p, = 38.5 Hz, Pw);13C(1H]NMR (C&, no Cyttp signals) 6 182.28 (9, CO), 180.71 (9, CO), 58.37 (9, CHZ), 58.24 (9, CH2), 30.57 (t, Jcp = 7.0 Hz, =CH), 26.41 (d, Jcp= 4.5 Hz, =CH), 14.94 (s, Me), 14.33 (s, Me). Anal. Calcd for C44H7604P3Re: C,55.73; H, 8.08. Found: C, 55.52; H, 7.89. Reaction of ReH,(ttp) with MeO2CCkCCO2Me (DMAD). A mixture of ReH,(ttp) (0.10 g, 0.13 mmol) and excess DMAD (0.20 mL, 1.6 mmol) in 25 mL of benzene was stirred for 4 h to give a dark brown solution. The solution was evaporated to dryness, and the residue was treated with 15 mL of Et& with stirring. The brown powder was collected on a filter frit, washed with a small amount of EhO,and dried under vacuum overnight: yield of Re(t$C(C0,Me)=CHC02Me)(Me02CCH= CHCOzMe)(ttp)(2a) 0.11 g (85%);IR (cm-', Nujol) v ( M ) 1730 (s), 1703 (s), 1695 (s), 1675 ( 8 ) ; 'H NMR (CsD,, 30 "C, no t t p signals) 6 7.96 (s, CH vinyl), 4.70 (br, HC=CH), 3.64 (s, Me), 3.07 (br, 2 Me), 2.54 (s, Me); 'H NMR (CD2C12,30 "C, no t t p signals) 6 4.42 (vbr, HC=CH), 3.69 (s, Me), 2.71 (s, Me); 'H N M R (CD2C12, -50 "C, no t t p signals) 6 4.35 (t, JHP = 7.8 Hz, HC=CH), 3.64 (s, Me), 3.48 (hr, 2 Me), 2.66 (d, J H =~ 2.2 Hz, Me); 31P(1H)NMR (CD2C12) 6 -20.90 (t, J p = 20.1 Hz, Pc),-26.84 (dd, J p p = 217.7, 20.1 Hz, Pw),-35.97 (d%.Jpp= 217.7,20.1 Hz, Pw);13C{lH)NMR (CD2C12,30 "C, no ttp signals) 6 179.69 (d, JcP = 11.1 Hz, CORe), 157.58 (s, CO), 165.98 (m, +Re), 122.90 ( 8 , CH vinyl), 51.55 (s, Me), 50.95 (s, Me), 50.55 (br, Me); 13C(1H) NMR (CD2Clz,-90 "C, no t t p signals) 6 185.84 (s, CO), 182.96 (s, CO), 179.13 (d, Jcp = 11.7 Hz, CORe), 169.07 (br, =CRe), 166.06 ( 8 , CO), 120.13 (s, CH vinyl), 51.88 (9, Me), 51.68 (s, Me), 50.95 (s, Me), 49.98 ( 8 , Me),

Notes Table 111. Positional and Equivalent Isotropic Thermal Parameters for 2a MeOH" BWbor B, atom X Y 2 A2 Re 0.007727 (24) 0.206459 (13) 0.260253 (12) 2.10 (1) P(1) 0.13971 (16) 0.112 115 (85) 0.254341 (85) 2.55 iaj P(2) 0.17953 (17) 0.272 477 (84) 0.227 954 (87) 2.58 (8) P(3) -0.11803 (17) 0.304 248 (85) 0.255 573 (85) 2.80 (8) O(1) -0.01017 (53) 0.31758 (26) 0.40900 (26) 4.5 (3) O(2) 0.19233 (51) 0.319 23 (27) 0.409 28 (26) 4.8 (3) O(3) 0.08326 (51) 0.106 99 (26) 0.420 03 (25) 4.5 (3) 0.10379 (25) 0.40901 (25) O(4) -0.121 25 (53) 4.4 (3) 0.11473 (30) 0.11890 (28) O(5) -0.16363 (51) 5.4 (3) 0.194 10 (21) 0.15345 (20) O(6) -0.04042 (41) 2.7 (2) 0.03825 (32) 0.259 16 (36) O(7) -0.39480 (67) 8.2 (4) 0.101 52 (29) 0.17259 (28) O(8) -0.37847 (52) 5.4 (3) c(l) 0.299 26 (61) 0.12462 (32) 0.28398 (34) 3.0 (3) 0.17821 (36) 0.24922 (36) C(2) 0.36793 (65) 3.5 (3) 0.248 09 (34) 0.262 89 (35) C(3) 0.32841 (63) 3.2 (3) 0.35859 (32) 0.251 48 (34) c(4) 0.18549 (66) 3.2 (3) 0.39749 (33) 0.22757 (35) C(5) 0.07425 (74) 3.6 (4) 0.383 75 (36) 0.263 38 (37) C(6) -0.04402 (69) 3.6 (4) 0.375 78 (44) 0.447 89 (43) C(7) -0.005 13 (93) 6.0 (5) 0.291 68 (39) 0.393 07 (32) C(8) 0.09842 (76) 3.7 (3) 0.229 53 (34) 0.35871 (31) C(9) 0.08633 (65) 3.0 (3) 0.191 92 (31) 0.361 80 (30) C(l0) -0.02569 (60) 2.6 (3) 0.13064 (35) 0.39853 (33) C(11) -0.011 50 (74) 3.2 (3) 0.045 28 (43) 0.447 75 (47) C(12) -0.1193 (IO) 6.6 (6) 0.12846 (63) 0.05292 (46) C(13) -0,12735 (94) 8.2 (7) 0.153 19 (34) 0.16499 (34) C(14) -0,11909 (63) 3.0 (3) 0.14827 (31) 0.23507 (33) C(15) -0.14571 (65) 2.9 (3) 0.114 76 (35) 0.262 16 (36) C(16) -0.23486 (68) 3.5 (4) C(17) -0.339 13 (78) 0.081 10 (39) 0.23075 (45) 4.5 (4) 0.06406 (50) 0.137 27 (47) C(18) -0.471 72 (85) 6.6 (6) 0.077 45 (31) 0.172 19 (32) C(19) 0.16797 (61) 2.6 (3) 0.011 39 (35) 0.163 11 (36) C(20) 0.18971 (70) 3.7 (4) C(21) 0.21845 (81) -0.011 76 (38) 0.101 92 (42) 4.6 (4) 0.029 11 (42) 0.04953 (40) C(22) 0.22731 (85) 4.9 (5) C(23) 0.208 26 (74) 0.094 40 (41) 0.057 63 (36) 4.1 (4) 0.11831 (33) 0.11832 (34) C(24) 0.17825 (62) 3.0 (3) 0.03596 (31) 0.29471 (32) C(25) 0.10077 (65) 2.9 (3) C(26) -0.00723 (69) 0.007 46 (36) 0.276 23 (38) 3.7 (4) C(27) -0.041 33 (79) -0.051 33 (39) 0.30380 (45) 4.8 (5) (C28) 0.03484 (88) -0.081 91 (38) 0.348 86 (45) 4.9 (5) C(29) 0.14346 (86) -0.053 25 (39) 0.367 60 (38) 4.5 (4) 0.005 58 (35) 0.341 39 (35) C(30) 0.17669 (70) 3.6 (4) 0.28054 (28) 0.13967 (32) C(31) 0.201 29 (61) 2.6 (3) 0.29438 (36) 0.09809 (33) C(32) 0.10285 (64) 3.4 (3) 0.303 05 (42) 0.032 43 (37) C(33) 0.11363 (72) 4.5 (4) 0.29700 (45) 0.00587 (37) C(34) 0.22547 (84) 5.0 (4) 0.282 30 (43) 0.046 66 (40) C(35) 0.32587 (76) 4.8 (4) 0.27482 (35) 0.11234 (37) C(36) 0.31504 (68) 3.5 (4) 0.31144 (33) 0.17695 (33) C(37) -0,20680 (66) 3.1 (3) 0.26365 (39) 0.16087 (36) C(38) -0.29237 (72) 3.9 (4) 0.262 02 (44) 0.099 75 (43) C(39) -0.35040 (79) 4.9 (5) C(40) -0.32583 (87) 0.30896 (49) 0.05405 (41) 5.3 (5) C(41) -0.24622 (85) 0.357 44 (48) 0.069 75 (42) 5.3 (5) 0.35862 (38) 0.13050 (39) C(42) -0.18609 (71) 4.1 (4) 0.31699 (37) 0.31098 (34) C(43) -0.244 50 (67) 3.3 (3) 0.26370 (40) 0.32807 (36) C(44) -0.31365 (71) 3.9 (4) 0.27035 (47) 0.36490 (40) C(45) -0.41657 (76) 4.8 (4) C(46) -0.44979 (83) 0.332 00 (57) 0.385 38 (43) 5.6 (5) C(47) -0.38171 (91) 0.383 85 (50) 0.369 58 (48) 6.0 (6) 0.376 86 (41) 0.332 52 (41) C(48) -0.28060 (75) 4.7 (4) 0.021 48 (85) 0.397 08 (82) 22.8 (7)* O(9) 0.5329 (16) 0.0722 (11) 0.4222 (11) C(49) 0.5198 (21) 18.2 (8)s Estimated standard deviations in the least significant figure(s) are given in parentheses. bThe form of the equivalent isotropic a i ~ a j desthermal parameter is B, = 8 / 3 ~ z ~ i ~ j U i j u i * u j *Asterisks ignate atoms refined isotropically. 36.42 (br, CH alkene), 28.89 (br, CH alkene). Anal. Calcd for C48H5208P3Re:C, 55.65; H, 5.06. Found: C, 56.28; H, 4.77. In another experiment, a solution of ReH6(ttp) (0.10 g, 0.13 mmol) in 25 mL of benzene was frozen a t ca. 0 OC, and a 2-fold wa8 added. The contents exceas of DMAD (0.050 mL, 0.41 "01) were warmed to room temperature and stirred for 30-45 min to give a light orange solution. (Longer reaction times lead also to

Organometallics, Vol. 11, No. 5, 1992 1967

Notes the formation of 2a, as ascertained by 31PNMR spectroscopy.) Solvent was removed, and 10 mL of hexane was added to the residue. The orange solid was collected on a filter frit, washed with a small amount of hexane, and dried under vacuum: yield 0.11 g (85%, assuming the product (3a) is isomeric with 2a); 'H NMR (C&, no ttp signals) 6 4.26 (t, JHP = 6.2 Hz, HC=CH), 3.42 (s, Me), 2.88 (8, Me), 1.56 (8, 2 Me); 31P(1H) NMR (C&) 6 -18.66 (t, J p = 12.5 Hz, Pc),-21.93 (dd, J p p = 179.2, 12.5 Hz, P,), -39.24 Jpp= 179.2, 12.5 Hz, P,). Reaction of ReH,(ttp) with Et02CC*C02Et (DEAD). The reaction procedure and workup were analogous to those for the synthesis of 2a, except that hexane was used to precipitate the product from benzene solution. Use of 0.10 g (0.13 mmol) of ReH5(Cyttp) and 0.20 mL (1.2 mmol) of DEAD yielded 0.11 g (79%) of Re($-C(C02Et)=CHC02Et)(Et02CCH= CHC02Et)(ttp) (2b): 'H NMR (C&, no ttp signals) 6 8.01 ( 8 , CH vinyl), 5.10 (br, HC=CH), -4.3 (m, 2 CH2), -3.7 (br, 2 CH2), NMR (C&) 1.19 (t, Me), 0.73 (br, 2 Me), 0.68 (t, Me); 31P(1H) 6 -20.29 (t, J p = 20.7 Hz, PA, -25.27 (dd, J p p = 218.9, 20.7 Hz, P,), -36.59 J p p = 218.9, 20.7 Hz, P,). S t r u c t u r e Determination of Re($(C,0)-C(CO2Me)= CHC02Me)(Me02CCH=CHC02Me)(ttp).MeoH (2a-MeOH). Crystals were grown by slow evaporation of solvent from a saturated solution of 2a in CH2C12/methanolunder a flow of Ar. The crystal used for data collection was cut from a large, dark brown, rectangular plate and coated with epoxy as a precaution against air decomposition. The space group is R 1 / n , and the cell constants were determined a t ambient temperature by a symmetry-restricted least-squares fit of the diffractometer setting angles for 25 reflections in the 28 range 29-30' with Mo K a radiation (X(Kn) = 0.71069 A). Data collection was done on a Rigaku AFC5S diffractometer. Six standard reflections were measured after every 150 reflections and indicated the crystal was stable. Data reduction and all additional calculations were done with the TEXSAN package of crystallographicprogramsP A +-scan absorption correction was applied to the data set.23 A summary of the crystal data and the details of the intensity data collection and refinement are provided in Table 11. The position of the Re atom was located on a Patterson map. The full structure was then elucidated by using the DIRDIF program%and standard Fourier methods. All least-squares refinements were of the full-matrix variety. A methanol molecule is also present in the asymmetric unit and appears to be disordered, since the thermal parameters for the carbon and oxygen atoms acquire large values and there are several peaks in the difference

&,

(&

(22)TEXSAN, TEXRAY Structure Analysis Package, version 2.1, Molecular Structure Corp., College Station, TX, 1987. (23)North, A. C. T.; Phillips, D. C.; Mathews, F. S. Acta Crystallogr. 1968, A24, 351. (24)Beurskens, P. T. DIRDIF: Direct Methods for Difference

Structures-An Automatic Procedure for Phase Extension and Refinement of Difference Structure Factors, Technical Report 1984/1;Crystallography Laboratory: Toernooiveld, 6525 Ed Nijmegen, The Netherlands, 1984.

electron density map in the immediate vicinity of this molecule. Several attempts at modeling this disorder were unsuccessful, and so the original model of just one position for this molecule was adopted with the thermal parameters kept at the isotropic level. After anisotropic refinement of the Re molecule the hydrogen atoms bonded to C(9), C(lO), and C(l6) were added to the model in their positions as located on a difference electron density msp. The phenyl ring hydrogen atoms and those on the CH2CH2CH2 bridges were included in the model in their calculated positions based on the assumptions C-H = 0.98 8,and BH= 1.2Bc(eq). The methyl group hydrogen atoms were idealized to tetrahedral geometry on the basis of their positions in the map. All hydrogen atoms were included as fixed contributions. No hydrogen atoms were added to the disordered methanol molecule. The final refinement cycle resulted in agreement indicss of R = 0.040 and R, = 0.042 based on the 6243 reflections with F,2 > 3dFO2)snd the 549 variables (anisotropic non-hydrogen atoms for the rhenium molecule, isotropic methanol molecule, hydrogen atoms fixed). The maximumand minimum peaks in the f i i difference electron density map have heights of +0.98 and -0.70 e/A3, with the maximum peak in the immediate vicinity of the methanol molecule. Scattering factors for neutral atoms were used and included terms for anomalous scattering.25 Final positional and equivalent isotropic thermal parameters are given in Table 111. Lists of anisotropic thermal parameters and hydrogen atom coordinates are available as supplementary material.26

Acknowledgment. We are grateful to the National Science Foundation and The Ohio State University for support. High-field NMR spectra were obtained at The Ohio State University Chemical Instrument Center (funded in part by the National Science Foundation, Grant 79-10019). We also thank Ms.Susan Reid for assistance with the solution and refinement of the structure. Registry No. la, 139870-86-3;lb, 139870-87-4;2a, 13989520-8; 2a*MeOH,139974-51-9; 2b, 139895-21-9; CyHp, 70786-89-9; Hp, 34989-06-5; DMAD, 762-42-5; DEAD, 762-21-0; ReH,(CyHp), 125952-2@7;ReH5(Hp),139970-885;ReC13(PMePhJ3, 80656-01-5; ReC13(CyHp), 125952-22-9; ReClJHp), 139870-89-6. Supplementary Material Available: Listings of anisotropic thermal parameters, hydrogen atom coordinates, torsion or conformation angles, additional bond distances and angles, and bond distances involving the hydrogen atoms and additional figures giving atom labeling for 2a-MeOH (16 pages). Ordering information is given on any current masthead page.

OM910650Z (25)Scattering factors for the non-hydrogen atoms and anomalous dispersion terms are from: International Tables for X-ray Crystallography; Kynoch Press: Birmingham, U.K., 1974;Vol. IV, pp 71,148.The scattering factor for the hydrogen atom is from: Stewart, R. F.; Davidson, E. R.; Simpson, W. T. J. Chem. Phys. 1965,42, 3175. (26)See the paragraph at the end of the paper regarding supplementary material.